X-Git-Url: https://main.carlh.net/gitweb/?p=dcpomatic.git;a=blobdiff_plain;f=src%2Flib%2Fframe_rate_change.cc;h=80a167029009349913b21e15c35d6aa0c760b4f2;hp=3e9c4b50528c4bf0fb3e4fe2fc786015d32c4a43;hb=422be0eece2bf6ee80db1d3c21553cd82efff789;hpb=8102046b2f29e0c7b234c29bf204b056cb30e64f

diff --git a/src/lib/frame_rate_change.cc b/src/lib/frame_rate_change.cc
index 3e9c4b505..80a167029 100644
--- a/src/lib/frame_rate_change.cc
+++ b/src/lib/frame_rate_change.cc
@@ -1,58 +1,43 @@
 /*
-    Copyright (C) 2012-2014 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2012-2016 Carl Hetherington <cth@carlh.net>
 
-    This program is free software; you can redistribute it and/or modify
+    This file is part of DCP-o-matic.
+
+    DCP-o-matic is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
     the Free Software Foundation; either version 2 of the License, or
     (at your option) any later version.
 
-    This program is distributed in the hope that it will be useful,
+    DCP-o-matic is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     GNU General Public License for more details.
 
     You should have received a copy of the GNU General Public License
-    along with this program; if not, write to the Free Software
-    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+    along with DCP-o-matic.  If not, see <http://www.gnu.org/licenses/>.
 
 */
 
-#include <cmath>
 #include "frame_rate_change.h"
+#include "types.h"
 #include "compose.hpp"
+#include <cmath>
 
 #include "i18n.h"
 
+using std::string;
+
 static bool
-about_equal (float a, float b)
+about_equal (double a, double b)
 {
-	/* A film of F seconds at f FPS will be Ff frames;
-	   Consider some delta FPS d, so if we run the same
-	   film at (f + d) FPS it will last F(f + d) seconds.
-
-	   Hence the difference in length over the length of the film will
-	   be F(f + d) - Ff frames
-	    = Ff + Fd - Ff frames
-	    = Fd frames
-	    = Fd/f seconds
- 
-	   So if we accept a difference of 1 frame, ie 1/f seconds, we can
-	   say that
-
-	   1/f = Fd/f
-	ie 1 = Fd
-	ie d = 1/F
- 
-	   So for a 3hr film, ie F = 3 * 60 * 60 = 10800, the acceptable
-	   FPS error is 1/F ~= 0.0001 ~= 10-e4
-	*/
-
-	return (fabs (a - b) < 1e-4);
+	return (fabs (a - b) < VIDEO_FRAME_RATE_EPSILON);
 }
 
 
-FrameRateChange::FrameRateChange (float source, int dcp)
-	: skip (false)
+FrameRateChange::FrameRateChange (double source_, int dcp_)
+	: source (source_)
+	, dcp (dcp_)
+	, skip (false)
 	, repeat (1)
 	, change_speed (false)
 {
@@ -71,6 +56,12 @@ FrameRateChange::FrameRateChange (float source, int dcp)
 
 	speed_up = dcp / (source * factor());
 	change_speed = !about_equal (speed_up, 1.0);
+}
+
+string
+FrameRateChange::description () const
+{
+	string description;
 
 	if (!skip && repeat == 1 && !change_speed) {
 		description = _("Content and DCP have the same rate.\n");
@@ -84,8 +75,10 @@ FrameRateChange::FrameRateChange (float source, int dcp)
 		}
 
 		if (change_speed) {
-			float const pc = dcp * 100 / (source * factor());
+			double const pc = dcp * 100 / (source * factor());
 			description += String::compose (_("DCP will run at %1%% of the content speed.\n"), pc);
 		}
 	}
+
+	return description;
 }